منابع مشابه
Connectivity of local tournaments
For a local tournament D with minimum out-degree δ, minimum indegree δ− and irregularity ig(D), we give a lower bound on the connectivity of D, namely κ(D) ≥ (2 ·max{δ+, δ−}+ 1− ig(D))/3 if there exists a minimum separating set S such that D − S i is a tournament, and κ(D) ≥ (2 ·max{δ+, δ−}+ 2|δ+ − δ−|+ 1− 2ig(D))/3 otherwise. This generalizes a result on tournaments presented by C. Thomassen [...
متن کاملLocal Tournaments and In - Tournaments
Preface Tournaments constitute perhaps the most well-studied class of directed graphs. One of the reasons for the interest in the theory of tournaments is the monograph Topics on Tournaments [58] by Moon published in 1968, covering all results on tournaments known up to this time. In particular, three results deserve special mention: in 1934 Rédei [60] proved that every tournament has a directe...
متن کاملPath - connect iv i ty in local tournaments 1
A digraph T is called a local tournament if for every vertex x of T, the set of in-neighbors as well as the set of out-neighbors of x induce tournaments. We give characterizations of generalized arc-pancyclic and strongly path-panconnected local tournaments, respectively. Our results generalize those due to Bu and Zhang (1996) about arc-pancyclic local tournaments and about strongly arc-pancycl...
متن کاملLongest path partitions in generalizations of tournaments
We consider the so-called Path Partition Conjecture for digraphs which states that for every digraph, D, and every choice of positive integers, λ1, λ2, such that λ1 + λ2 equals the order of a longest directed path in D, there exists a partition of D into two digraphs, D1 and D2, such that the order of a longest path in Di is at most λi, for i = 1, 2. We prove that certain classes of digraphs, w...
متن کاملOn two-path convexity in multipartite tournaments
In the context of two-path convexity, we study the rank, Helly number, Radon number, Caratheodory number, and hull number for multipartite tournaments. We show the maximum Caratheodory number of a multipartite tournament is 3. We then derive tight upper bounds for rank in both general multipartite tournaments and clone-free multipartite tournaments. We show that these same tight upper bounds ho...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1997
ISSN: 0012-365X
DOI: 10.1016/s0012-365x(96)00240-3